Petroleum distillation



Sept 2 1930- A. MCD. MCAFEE ET AL PETROLEUM DISTILLATION Filed Sept. 1'7, 1926 Patented Sept. 2, 1930 UNITED STATES PATENT oFFlcE ALMEB MODUFFIE IOAFEE AND BONNEB H. BARNES, OF PORT ARTHUR, TEXAS, AS- SIGNORS TO GULF REFINING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A. COR- PORATION OF TEXAS PETROLEUM DIsTILLATIoN Application led September 17, 1926.*"Serial lNo. 186,100.

This invention relates to petroleum distillation; and it comprises a method of obviating the ill elfects of acid petroleum vapors on still walls in operations involving displacement of such vapors by steam blown into the still above the oil level wherein the incoming steam carries a modicum of alkaline material, usually occurring as a spray of caustic soda solution; all as more' fully hereinafter set forth and as claimed.

In various relations in the art of petroleum distillation it is necessary to introduce steam into the vapor space of la still at a time when the walls of the still and the vapors in the still may carry acid matters causing corrosion with the aid of such steam. For example, in a.

prior Patent 1,578,053, March 23, 1926, Mc- Afee has described and claimed a process of removing residues from stills for converting high boiling oils into low boiling oils and operation with the use of aluminum chlorid.

In the routine of the process described and claimed, one operation is displacing oil vapors in the still by steam blown in at the top. In this operation, it has now been found of great advantage to alkalize the steam some'- what, thereby neutralizing any acid which may develop y h drolytic action ofthe steam on aluminumch orid, as well as decomposing any aluminum chlorid which may be present as such on the walls ofthe still. Alkalization may be effected in various ways; but the most convenient way is to spray a I `solution of caustic soda into the current of' ingoing steam. 'Carbonate of soda (ordinary soda ash) may be used but itis not more advantageous; nor is it as convenient to handle. The same is true of milk of lime and a variety of other alkaline materials. Ammonia gas can be used but is ordinarily precluded by considerations of' cost.

The same principle of usin steam to protect still walls is o advantage in various other-relations in petroleum reining .Where it is necessary or desirable to displace acid vapors by steam. In many methods of handling petroleum oils it bef.

comes necessary to d istil a somewhat acid oil after a treatment with sulfuric acid and we have found it an advantage in such distillaalkalized l head steam in this way isan advantage in petroleum distillation, even where no prior acid treatment has been used. For example, many crudes carry enough acidity to make use of a little alkalized top steam of advantage in prolonging the life of the still and of the va or line. A

In t e accompanying drawing is shown, more or less diagrammatically, an apparatus utilizing the present invention. The view 1s in central vertical section, certain parts being in elevation.

T he figure is intended to illustrate the utilization of the present invention in such a process as that described in the acknowled ed Patent 1,578,053. In this showinglement 1 is a. still of known type for utilizing the convertingaction of aluminum chlorid on high boiling oils. It is provided with internal stirring mechanism 2 and is supported on the furnace walls 3. The still is provided with tar plug/1 operated by rod 5. It carries the usual manhole 6 and vapor outlet means 7 leading to condensers (not shown). Lines 8 and 9 are provided for pumping up and/or circulating the oil which the still is washed out. VThe present invention relates more particularly-to the use space of the still and displacement of them of steam through 10.y As shown, line 10 is by the mixture of steam and alkali.

provided with gate valve 11 and injector 12.

In testimony whereof, we have hereunto af- Above the injector is lock box 13 into which fixed our signatures, at Port Arthur, Texas, passes caustic soda solution via needle valve thls 14th day of September, 1926. .m

14 and pipe 15. Pipe 15 communicates with pipe 16 leading to-any suitable source of any convenient alkali, such as caustic soda solution, under such pump pressure as may be desired. Steam enters the system through pipe 17 provided with valves 18 and 19 and having valved steam b leed 20.

As will be seen, during the blowout stage of the operation of the still, the entering steam can receive an addition of any desired amount of any convenient alkali.

In using the present invention with other stills, the 'organization illustrated in connection with pipe 10 is ordinarily employed; pipe 10, in such a case, entering the still at any point where top steam is usually introduced.

1. In the distillation of petroleum oils under conditions wherein the vapors produced contain acids, the process of removing such acid vapors from the still upon cessation of the distillation, which comprises blowing alkalized steam into the vapor space of the still, and allowing the vapors displaced thereby to escape from the still.

2. In the distillation of petroleum hydrocarbons by means of aluminum chlorid wherein acid vapors are formed, the process of removing such acid vapors from the still at the conclusion of the distillation by introducing into the vapor space of the still suflicient alkalized steam to displace the vapors, and

allowing the vaporsto escape from the still.

3. The process of preserving metal receptacles in which vapors of acid character have been produced through the heating of petroleum oils, which comprises forcing alkalized steam into the upper part of the receptacle where vapors have collected after such heating and allowing the vapors to escape and be displaced by sai-d steam.

4. In the distillation of petroleum oils under conditions wherein the vapors produced contain acids, the process of removing such acid vapors from the still upon cessation of the distillation by blowing a mixture of steam and caustic soda solution into the vapor space of the still, and allowing the vapors displaced thereby to escape from the still.

5. In the distillation of petroleum hydrocarbons under conditions wherein acid vapors are produced, the rocess of removing such acide vaporsfrom t e vapor space of the still at the conclusion of the distillation, which com rises admitting steam to the vapor space of t e still, addin to the steam on its way to the still a solutlon of an alkali, and permitting escape of the vapors from the vapor ALMER MCDUFFIE MCAFEE. BONNER H.A BARNES. 

